python demo_toolbox.py

Arguments:
datasets_root: None
vc_mode: False
enc_models_dir: encoder/saved_models
syn_models_dir: synthesizer/saved_models
voc_models_dir: vocoder/saved_models
extractor_models_dir: ppg_extractor/saved_models
convertor_models_dir: ppg2mel/saved_models
cpu: False
seed: None
no_mp3_support: False

qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl, xcb.

Start by running python demo_toolbox.py and compare its startup behavior with the reported Qt xcb display error. Trace the entry point's display initialization and establish whether the intended result is successful startup in a graphical environment or a clear fallback when no display is available.

Written by the indexing model from the issue text.